drivers/hwmon/pmbus/ltc2978.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Hardware monitoring driver for LTC2978 and compatible chips.
   4  *
   5  * Copyright (c) 2011 Ericsson AB.
   6  * Copyright (c) 2013, 2014, 2015 Guenter Roeck
   7  * Copyright (c) 2015 Linear Technology
   8  * Copyright (c) 2018 Analog Devices Inc.
   9  */
  10
  11 #include <linux/delay.h>
  12 #include <linux/jiffies.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/err.h>
  17 #include <linux/slab.h>
  18 #include <linux/i2c.h>
  19 #include <linux/regulator/driver.h>
  20 #include "pmbus.h"
  21
  22 enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882,
  23         ltc3883, ltc3886, ltc3887, ltm2987, ltm4675, ltm4676, ltm4686 };
  24
  25 /* Common for all chips */
  26 #define LTC2978_MFR_VOUT_PEAK           0xdd
  27 #define LTC2978_MFR_VIN_PEAK            0xde
  28 #define LTC2978_MFR_TEMPERATURE_PEAK    0xdf
  29 #define LTC2978_MFR_SPECIAL_ID          0xe7    /* Undocumented on LTC3882 */
  30 #define LTC2978_MFR_COMMON              0xef
  31
  32 /* LTC2974, LTC2975, LCT2977, LTC2980, LTC2978, and LTM2987 */
  33 #define LTC2978_MFR_VOUT_MIN            0xfb
  34 #define LTC2978_MFR_VIN_MIN             0xfc
  35 #define LTC2978_MFR_TEMPERATURE_MIN     0xfd
  36
  37 /* LTC2974, LTC2975 */
  38 #define LTC2974_MFR_IOUT_PEAK           0xd7
  39 #define LTC2974_MFR_IOUT_MIN            0xd8
  40
  41 /* LTC3880, LTC3882, LTC3883, LTC3887, LTM4675, and LTM4676 */
  42 #define LTC3880_MFR_IOUT_PEAK           0xd7
  43 #define LTC3880_MFR_CLEAR_PEAKS         0xe3
  44 #define LTC3880_MFR_TEMPERATURE2_PEAK   0xf4
  45
  46 /* LTC3883 and LTC3886 only */
  47 #define LTC3883_MFR_IIN_PEAK            0xe1
  48
  49 /* LTC2975 only */
  50 #define LTC2975_MFR_IIN_PEAK            0xc4
  51 #define LTC2975_MFR_IIN_MIN             0xc5
  52 #define LTC2975_MFR_PIN_PEAK            0xc6
  53 #define LTC2975_MFR_PIN_MIN             0xc7
  54
  55 #define LTC2978_ID_MASK                 0xfff0
  56
  57 #define LTC2974_ID                      0x0210
  58 #define LTC2975_ID                      0x0220
  59 #define LTC2977_ID                      0x0130
  60 #define LTC2978_ID_REV1                 0x0110  /* Early revision */
  61 #define LTC2978_ID_REV2                 0x0120
  62 #define LTC2980_ID_A                    0x8030  /* A/B for two die IDs */
  63 #define LTC2980_ID_B                    0x8040
  64 #define LTC3880_ID                      0x4020
  65 #define LTC3882_ID                      0x4200
  66 #define LTC3882_ID_D1                   0x4240  /* Dash 1 */
  67 #define LTC3883_ID                      0x4300
  68 #define LTC3886_ID                      0x4600
  69 #define LTC3887_ID                      0x4700
  70 #define LTM2987_ID_A                    0x8010  /* A/B for two die IDs */
  71 #define LTM2987_ID_B                    0x8020
  72 #define LTM4675_ID                      0x47a0
  73 #define LTM4676_ID_REV1                 0x4400
  74 #define LTM4676_ID_REV2                 0x4480
  75 #define LTM4676A_ID                     0x47e0
  76 #define LTM4686_ID                      0x4770
  77
  78 #define LTC2974_NUM_PAGES               4
  79 #define LTC2978_NUM_PAGES               8
  80 #define LTC3880_NUM_PAGES               2
  81 #define LTC3883_NUM_PAGES               1
  82
  83 #define LTC_POLL_TIMEOUT                100     /* in milli-seconds */
  84
  85 #define LTC_NOT_BUSY                    BIT(5)
  86 #define LTC_NOT_PENDING                 BIT(4)
  87
  88 /*
  89  * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which
  90  * happens pretty much each time chip data is updated. Raw peak data therefore
  91  * does not provide much value. To be able to provide useful peak data, keep an
  92  * internal cache of measured peak data, which is only cleared if an explicit
  93  * "clear peak" command is executed for the sensor in question.
  94  */
  95
  96 struct ltc2978_data {
  97         enum chips id;
  98         u16 vin_min, vin_max;
  99         u16 temp_min[LTC2974_NUM_PAGES], temp_max[LTC2974_NUM_PAGES];
 100         u16 vout_min[LTC2978_NUM_PAGES], vout_max[LTC2978_NUM_PAGES];
 101         u16 iout_min[LTC2974_NUM_PAGES], iout_max[LTC2974_NUM_PAGES];
 102         u16 iin_min, iin_max;
 103         u16 pin_min, pin_max;
 104         u16 temp2_max;
 105         struct pmbus_driver_info info;
 106         u32 features;
 107 };
 108 #define to_ltc2978_data(x)  container_of(x, struct ltc2978_data, info)
 109
 110 #define FEAT_CLEAR_PEAKS        BIT(0)
 111 #define FEAT_NEEDS_POLLING      BIT(1)
 112
 113 #define has_clear_peaks(d)      ((d)->features & FEAT_CLEAR_PEAKS)
 114 #define needs_polling(d)        ((d)->features & FEAT_NEEDS_POLLING)
 115
 116 static int ltc_wait_ready(struct i2c_client *client)
 117 {
 118         unsigned long timeout = jiffies + msecs_to_jiffies(LTC_POLL_TIMEOUT);
 119         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 120         struct ltc2978_data *data = to_ltc2978_data(info);
 121         int status;
 122         u8 mask;
 123
 124         if (!needs_polling(data))
 125                 return 0;
 126
 127         /*
 128          * LTC3883 does not support LTC_NOT_PENDING, even though
 129          * the datasheet claims that it does.
 130          */
 131         mask = LTC_NOT_BUSY;
 132         if (data->id != ltc3883)
 133                 mask |= LTC_NOT_PENDING;
 134
 135         do {
 136                 status = pmbus_read_byte_data(client, 0, LTC2978_MFR_COMMON);
 137                 if (status == -EBADMSG || status == -ENXIO) {
 138                         /* PEC error or NACK: chip may be busy, try again */
 139                         usleep_range(50, 100);
 140                         continue;
 141                 }
 142                 if (status < 0)
 143                         return status;
 144
 145                 if ((status & mask) == mask)
 146                         return 0;
 147
 148                 usleep_range(50, 100);
 149         } while (time_before(jiffies, timeout));
 150
 151         return -ETIMEDOUT;
 152 }
 153
 154 static int ltc_read_word_data(struct i2c_client *client, int page, int reg)
 155 {
 156         int ret;
 157
 158         ret = ltc_wait_ready(client);
 159         if (ret < 0)
 160                 return ret;
 161
 162         return pmbus_read_word_data(client, page, reg);
 163 }
 164
 165 static int ltc_read_byte_data(struct i2c_client *client, int page, int reg)
 166 {
 167         int ret;
 168
 169         ret = ltc_wait_ready(client);
 170         if (ret < 0)
 171                 return ret;
 172
 173         return pmbus_read_byte_data(client, page, reg);
 174 }
 175
 176 static int ltc_write_byte(struct i2c_client *client, int page, u8 byte)
 177 {
 178         int ret;
 179
 180         ret = ltc_wait_ready(client);
 181         if (ret < 0)
 182                 return ret;
 183
 184         return pmbus_write_byte(client, page, byte);
 185 }
 186
 187 static inline int lin11_to_val(int data)
 188 {
 189         s16 e = ((s16)data) >> 11;
 190         s32 m = (((s16)(data << 5)) >> 5);
 191
 192         /*
 193          * mantissa is 10 bit + sign, exponent adds up to 15 bit.
 194          * Add 6 bit to exponent for maximum accuracy (10 + 15 + 6 = 31).
 195          */
 196         e += 6;
 197         return (e < 0 ? m >> -e : m << e);
 198 }
 199
 200 static int ltc_get_max(struct ltc2978_data *data, struct i2c_client *client,
 201                        int page, int reg, u16 *pmax)
 202 {
 203         int ret;
 204
 205         ret = ltc_read_word_data(client, page, reg);
 206         if (ret >= 0) {
 207                 if (lin11_to_val(ret) > lin11_to_val(*pmax))
 208                         *pmax = ret;
 209                 ret = *pmax;
 210         }
 211         return ret;
 212 }
 213
 214 static int ltc_get_min(struct ltc2978_data *data, struct i2c_client *client,
 215                        int page, int reg, u16 *pmin)
 216 {
 217         int ret;
 218
 219         ret = ltc_read_word_data(client, page, reg);
 220         if (ret >= 0) {
 221                 if (lin11_to_val(ret) < lin11_to_val(*pmin))
 222                         *pmin = ret;
 223                 ret = *pmin;
 224         }
 225         return ret;
 226 }
 227
 228 static int ltc2978_read_word_data_common(struct i2c_client *client, int page,
 229                                          int reg)
 230 {
 231         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 232         struct ltc2978_data *data = to_ltc2978_data(info);
 233         int ret;
 234
 235         switch (reg) {
 236         case PMBUS_VIRT_READ_VIN_MAX:
 237                 ret = ltc_get_max(data, client, page, LTC2978_MFR_VIN_PEAK,
 238                                   &data->vin_max);
 239                 break;
 240         case PMBUS_VIRT_READ_VOUT_MAX:
 241                 ret = ltc_read_word_data(client, page, LTC2978_MFR_VOUT_PEAK);
 242                 if (ret >= 0) {
 243                         /*
 244                          * VOUT is 16 bit unsigned with fixed exponent,
 245                          * so we can compare it directly
 246                          */
 247                         if (ret > data->vout_max[page])
 248                                 data->vout_max[page] = ret;
 249                         ret = data->vout_max[page];
 250                 }
 251                 break;
 252         case PMBUS_VIRT_READ_TEMP_MAX:
 253                 ret = ltc_get_max(data, client, page,
 254                                   LTC2978_MFR_TEMPERATURE_PEAK,
 255                                   &data->temp_max[page]);
 256                 break;
 257         case PMBUS_VIRT_RESET_VOUT_HISTORY:
 258         case PMBUS_VIRT_RESET_VIN_HISTORY:
 259         case PMBUS_VIRT_RESET_TEMP_HISTORY:
 260                 ret = 0;
 261                 break;
 262         default:
 263                 ret = ltc_wait_ready(client);
 264                 if (ret < 0)
 265                         return ret;
 266                 ret = -ENODATA;
 267                 break;
 268         }
 269         return ret;
 270 }
 271
 272 static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
 273 {
 274         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 275         struct ltc2978_data *data = to_ltc2978_data(info);
 276         int ret;
 277
 278         switch (reg) {
 279         case PMBUS_VIRT_READ_VIN_MIN:
 280                 ret = ltc_get_min(data, client, page, LTC2978_MFR_VIN_MIN,
 281                                   &data->vin_min);
 282                 break;
 283         case PMBUS_VIRT_READ_VOUT_MIN:
 284                 ret = ltc_read_word_data(client, page, LTC2978_MFR_VOUT_MIN);
 285                 if (ret >= 0) {
 286                         /*
 287                          * VOUT_MIN is known to not be supported on some lots
 288                          * of LTC2978 revision 1, and will return the maximum
 289                          * possible voltage if read. If VOUT_MAX is valid and
 290                          * lower than the reading of VOUT_MIN, use it instead.
 291                          */
 292                         if (data->vout_max[page] && ret > data->vout_max[page])
 293                                 ret = data->vout_max[page];
 294                         if (ret < data->vout_min[page])
 295                                 data->vout_min[page] = ret;
 296                         ret = data->vout_min[page];
 297                 }
 298                 break;
 299         case PMBUS_VIRT_READ_TEMP_MIN:
 300                 ret = ltc_get_min(data, client, page,
 301                                   LTC2978_MFR_TEMPERATURE_MIN,
 302                                   &data->temp_min[page]);
 303                 break;
 304         case PMBUS_VIRT_READ_IOUT_MAX:
 305         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 306         case PMBUS_VIRT_READ_TEMP2_MAX:
 307         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 308                 ret = -ENXIO;
 309                 break;
 310         default:
 311                 ret = ltc2978_read_word_data_common(client, page, reg);
 312                 break;
 313         }
 314         return ret;
 315 }
 316
 317 static int ltc2974_read_word_data(struct i2c_client *client, int page, int reg)
 318 {
 319         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 320         struct ltc2978_data *data = to_ltc2978_data(info);
 321         int ret;
 322
 323         switch (reg) {
 324         case PMBUS_VIRT_READ_IOUT_MAX:
 325                 ret = ltc_get_max(data, client, page, LTC2974_MFR_IOUT_PEAK,
 326                                   &data->iout_max[page]);
 327                 break;
 328         case PMBUS_VIRT_READ_IOUT_MIN:
 329                 ret = ltc_get_min(data, client, page, LTC2974_MFR_IOUT_MIN,
 330                                   &data->iout_min[page]);
 331                 break;
 332         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 333                 ret = 0;
 334                 break;
 335         default:
 336                 ret = ltc2978_read_word_data(client, page, reg);
 337                 break;
 338         }
 339         return ret;
 340 }
 341
 342 static int ltc2975_read_word_data(struct i2c_client *client, int page, int reg)
 343 {
 344         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 345         struct ltc2978_data *data = to_ltc2978_data(info);
 346         int ret;
 347
 348         switch (reg) {
 349         case PMBUS_VIRT_READ_IIN_MAX:
 350                 ret = ltc_get_max(data, client, page, LTC2975_MFR_IIN_PEAK,
 351                                   &data->iin_max);
 352                 break;
 353         case PMBUS_VIRT_READ_IIN_MIN:
 354                 ret = ltc_get_min(data, client, page, LTC2975_MFR_IIN_MIN,
 355                                   &data->iin_min);
 356                 break;
 357         case PMBUS_VIRT_READ_PIN_MAX:
 358                 ret = ltc_get_max(data, client, page, LTC2975_MFR_PIN_PEAK,
 359                                   &data->pin_max);
 360                 break;
 361         case PMBUS_VIRT_READ_PIN_MIN:
 362                 ret = ltc_get_min(data, client, page, LTC2975_MFR_PIN_MIN,
 363                                   &data->pin_min);
 364                 break;
 365         case PMBUS_VIRT_RESET_IIN_HISTORY:
 366         case PMBUS_VIRT_RESET_PIN_HISTORY:
 367                 ret = 0;
 368                 break;
 369         default:
 370                 ret = ltc2978_read_word_data(client, page, reg);
 371                 break;
 372         }
 373         return ret;
 374 }
 375
 376 static int ltc3880_read_word_data(struct i2c_client *client, int page, int reg)
 377 {
 378         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 379         struct ltc2978_data *data = to_ltc2978_data(info);
 380         int ret;
 381
 382         switch (reg) {
 383         case PMBUS_VIRT_READ_IOUT_MAX:
 384                 ret = ltc_get_max(data, client, page, LTC3880_MFR_IOUT_PEAK,
 385                                   &data->iout_max[page]);
 386                 break;
 387         case PMBUS_VIRT_READ_TEMP2_MAX:
 388                 ret = ltc_get_max(data, client, page,
 389                                   LTC3880_MFR_TEMPERATURE2_PEAK,
 390                                   &data->temp2_max);
 391                 break;
 392         case PMBUS_VIRT_READ_VIN_MIN:
 393         case PMBUS_VIRT_READ_VOUT_MIN:
 394         case PMBUS_VIRT_READ_TEMP_MIN:
 395                 ret = -ENXIO;
 396                 break;
 397         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 398         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 399                 ret = 0;
 400                 break;
 401         default:
 402                 ret = ltc2978_read_word_data_common(client, page, reg);
 403                 break;
 404         }
 405         return ret;
 406 }
 407
 408 static int ltc3883_read_word_data(struct i2c_client *client, int page, int reg)
 409 {
 410         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 411         struct ltc2978_data *data = to_ltc2978_data(info);
 412         int ret;
 413
 414         switch (reg) {
 415         case PMBUS_VIRT_READ_IIN_MAX:
 416                 ret = ltc_get_max(data, client, page, LTC3883_MFR_IIN_PEAK,
 417                                   &data->iin_max);
 418                 break;
 419         case PMBUS_VIRT_RESET_IIN_HISTORY:
 420                 ret = 0;
 421                 break;
 422         default:
 423                 ret = ltc3880_read_word_data(client, page, reg);
 424                 break;
 425         }
 426         return ret;
 427 }
 428
 429 static int ltc2978_clear_peaks(struct ltc2978_data *data,
 430                                struct i2c_client *client, int page)
 431 {
 432         int ret;
 433
 434         if (has_clear_peaks(data))
 435                 ret = ltc_write_byte(client, 0, LTC3880_MFR_CLEAR_PEAKS);
 436         else
 437                 ret = ltc_write_byte(client, page, PMBUS_CLEAR_FAULTS);
 438
 439         return ret;
 440 }
 441
 442 static int ltc2978_write_word_data(struct i2c_client *client, int page,
 443                                     int reg, u16 word)
 444 {
 445         const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
 446         struct ltc2978_data *data = to_ltc2978_data(info);
 447         int ret;
 448
 449         switch (reg) {
 450         case PMBUS_VIRT_RESET_IIN_HISTORY:
 451                 data->iin_max = 0x7c00;
 452                 data->iin_min = 0x7bff;
 453                 ret = ltc2978_clear_peaks(data, client, 0);
 454                 break;
 455         case PMBUS_VIRT_RESET_PIN_HISTORY:
 456                 data->pin_max = 0x7c00;
 457                 data->pin_min = 0x7bff;
 458                 ret = ltc2978_clear_peaks(data, client, 0);
 459                 break;
 460         case PMBUS_VIRT_RESET_IOUT_HISTORY:
 461                 data->iout_max[page] = 0x7c00;
 462                 data->iout_min[page] = 0xfbff;
 463                 ret = ltc2978_clear_peaks(data, client, page);
 464                 break;
 465         case PMBUS_VIRT_RESET_TEMP2_HISTORY:
 466                 data->temp2_max = 0x7c00;
 467                 ret = ltc2978_clear_peaks(data, client, page);
 468                 break;
 469         case PMBUS_VIRT_RESET_VOUT_HISTORY:
 470                 data->vout_min[page] = 0xffff;
 471                 data->vout_max[page] = 0;
 472                 ret = ltc2978_clear_peaks(data, client, page);
 473                 break;
 474         case PMBUS_VIRT_RESET_VIN_HISTORY:
 475                 data->vin_min = 0x7bff;
 476                 data->vin_max = 0x7c00;
 477                 ret = ltc2978_clear_peaks(data, client, page);
 478                 break;
 479         case PMBUS_VIRT_RESET_TEMP_HISTORY:
 480                 data->temp_min[page] = 0x7bff;
 481                 data->temp_max[page] = 0x7c00;
 482                 ret = ltc2978_clear_peaks(data, client, page);
 483                 break;
 484         default:
 485                 ret = ltc_wait_ready(client);
 486                 if (ret < 0)
 487                         return ret;
 488                 ret = -ENODATA;
 489                 break;
 490         }
 491         return ret;
 492 }
 493
 494 static const struct i2c_device_id ltc2978_id[] = {
 495         {"ltc2974", ltc2974},
 496         {"ltc2975", ltc2975},
 497         {"ltc2977", ltc2977},
 498         {"ltc2978", ltc2978},
 499         {"ltc2980", ltc2980},
 500         {"ltc3880", ltc3880},
 501         {"ltc3882", ltc3882},
 502         {"ltc3883", ltc3883},
 503         {"ltc3886", ltc3886},
 504         {"ltc3887", ltc3887},
 505         {"ltm2987", ltm2987},
 506         {"ltm4675", ltm4675},
 507         {"ltm4676", ltm4676},
 508         {"ltm4686", ltm4686},
 509         {}
 510 };
 511 MODULE_DEVICE_TABLE(i2c, ltc2978_id);
 512
 513 #if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
 514 static const struct regulator_desc ltc2978_reg_desc[] = {
 515         PMBUS_REGULATOR("vout", 0),
 516         PMBUS_REGULATOR("vout", 1),
 517         PMBUS_REGULATOR("vout", 2),
 518         PMBUS_REGULATOR("vout", 3),
 519         PMBUS_REGULATOR("vout", 4),
 520         PMBUS_REGULATOR("vout", 5),
 521         PMBUS_REGULATOR("vout", 6),
 522         PMBUS_REGULATOR("vout", 7),
 523 };
 524 #endif /* CONFIG_SENSORS_LTC2978_REGULATOR */
 525
 526 static int ltc2978_get_id(struct i2c_client *client)
 527 {
 528         int chip_id;
 529
 530         chip_id = i2c_smbus_read_word_data(client, LTC2978_MFR_SPECIAL_ID);
 531         if (chip_id < 0) {
 532                 const struct i2c_device_id *id;
 533                 u8 buf[I2C_SMBUS_BLOCK_MAX];
 534                 int ret;
 535
 536                 if (!i2c_check_functionality(client->adapter,
 537                                              I2C_FUNC_SMBUS_READ_BLOCK_DATA))
 538                         return -ENODEV;
 539
 540                 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
 541                 if (ret < 0)
 542                         return ret;
 543                 if (ret < 3 || strncmp(buf, "LTC", 3))
 544                         return -ENODEV;
 545
 546                 ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
 547                 if (ret < 0)
 548                         return ret;
 549                 for (id = &ltc2978_id[0]; strlen(id->name); id++) {
 550                         if (!strncasecmp(id->name, buf, strlen(id->name)))
 551                                 return (int)id->driver_data;
 552                 }
 553                 return -ENODEV;
 554         }
 555
 556         chip_id &= LTC2978_ID_MASK;
 557
 558         if (chip_id == LTC2974_ID)
 559                 return ltc2974;
 560         else if (chip_id == LTC2975_ID)
 561                 return ltc2975;
 562         else if (chip_id == LTC2977_ID)
 563                 return ltc2977;
 564         else if (chip_id == LTC2978_ID_REV1 || chip_id == LTC2978_ID_REV2)
 565                 return ltc2978;
 566         else if (chip_id == LTC2980_ID_A || chip_id == LTC2980_ID_B)
 567                 return ltc2980;
 568         else if (chip_id == LTC3880_ID)
 569                 return ltc3880;
 570         else if (chip_id == LTC3882_ID || chip_id == LTC3882_ID_D1)
 571                 return ltc3882;
 572         else if (chip_id == LTC3883_ID)
 573                 return ltc3883;
 574         else if (chip_id == LTC3886_ID)
 575                 return ltc3886;
 576         else if (chip_id == LTC3887_ID)
 577                 return ltc3887;
 578         else if (chip_id == LTM2987_ID_A || chip_id == LTM2987_ID_B)
 579                 return ltm2987;
 580         else if (chip_id == LTM4675_ID)
 581                 return ltm4675;
 582         else if (chip_id == LTM4676_ID_REV1 || chip_id == LTM4676_ID_REV2 ||
 583                  chip_id == LTM4676A_ID)
 584                 return ltm4676;
 585         else if (chip_id == LTM4686_ID)
 586                 return ltm4686;
 587
 588         dev_err(&client->dev, "Unsupported chip ID 0x%x\n", chip_id);
 589         return -ENODEV;
 590 }
 591
 592 static int ltc2978_probe(struct i2c_client *client,
 593                          const struct i2c_device_id *id)
 594 {
 595         int i, chip_id;
 596         struct ltc2978_data *data;
 597         struct pmbus_driver_info *info;
 598
 599         if (!i2c_check_functionality(client->adapter,
 600                                      I2C_FUNC_SMBUS_READ_WORD_DATA))
 601                 return -ENODEV;
 602
 603         data = devm_kzalloc(&client->dev, sizeof(struct ltc2978_data),
 604                             GFP_KERNEL);
 605         if (!data)
 606                 return -ENOMEM;
 607
 608         chip_id = ltc2978_get_id(client);
 609         if (chip_id < 0)
 610                 return chip_id;
 611
 612         data->id = chip_id;
 613         if (data->id != id->driver_data)
 614                 dev_warn(&client->dev,
 615                          "Device mismatch: Configured %s, detected %s\n",
 616                          id->name,
 617                          ltc2978_id[data->id].name);
 618
 619         info = &data->info;
 620         info->write_word_data = ltc2978_write_word_data;
 621         info->write_byte = ltc_write_byte;
 622         info->read_word_data = ltc_read_word_data;
 623         info->read_byte_data = ltc_read_byte_data;
 624
 625         data->vin_min = 0x7bff;
 626         data->vin_max = 0x7c00;
 627         for (i = 0; i < ARRAY_SIZE(data->vout_min); i++)
 628                 data->vout_min[i] = 0xffff;
 629         for (i = 0; i < ARRAY_SIZE(data->iout_min); i++)
 630                 data->iout_min[i] = 0xfbff;
 631         for (i = 0; i < ARRAY_SIZE(data->iout_max); i++)
 632                 data->iout_max[i] = 0x7c00;
 633         for (i = 0; i < ARRAY_SIZE(data->temp_min); i++)
 634                 data->temp_min[i] = 0x7bff;
 635         for (i = 0; i < ARRAY_SIZE(data->temp_max); i++)
 636                 data->temp_max[i] = 0x7c00;
 637         data->temp2_max = 0x7c00;
 638
 639         switch (data->id) {
 640         case ltc2974:
 641                 info->read_word_data = ltc2974_read_word_data;
 642                 info->pages = LTC2974_NUM_PAGES;
 643                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 644                   | PMBUS_HAVE_TEMP2;
 645                 for (i = 0; i < info->pages; i++) {
 646                         info->func[i] |= PMBUS_HAVE_VOUT
 647                           | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
 648                           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 649                           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 650                 }
 651                 break;
 652         case ltc2975:
 653                 info->read_word_data = ltc2975_read_word_data;
 654                 info->pages = LTC2974_NUM_PAGES;
 655                 info->func[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN
 656                   | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 657                   | PMBUS_HAVE_TEMP2;
 658                 for (i = 0; i < info->pages; i++) {
 659                         info->func[i] |= PMBUS_HAVE_VOUT
 660                           | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_POUT
 661                           | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 662                           | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT;
 663                 }
 664                 break;
 665         case ltc2977:
 666         case ltc2978:
 667         case ltc2980:
 668         case ltm2987:
 669                 info->read_word_data = ltc2978_read_word_data;
 670                 info->pages = LTC2978_NUM_PAGES;
 671                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
 672                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 673                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 674                 for (i = 1; i < LTC2978_NUM_PAGES; i++) {
 675                         info->func[i] = PMBUS_HAVE_VOUT
 676                           | PMBUS_HAVE_STATUS_VOUT;
 677                 }
 678                 break;
 679         case ltc3880:
 680         case ltc3887:
 681         case ltm4675:
 682         case ltm4676:
 683         case ltm4686:
 684                 data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
 685                 info->read_word_data = ltc3880_read_word_data;
 686                 info->pages = LTC3880_NUM_PAGES;
 687                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
 688                   | PMBUS_HAVE_STATUS_INPUT
 689                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 690                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 691                   | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 692                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 693                 info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 694                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 695                   | PMBUS_HAVE_POUT
 696                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 697                 break;
 698         case ltc3882:
 699                 data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
 700                 info->read_word_data = ltc3880_read_word_data;
 701                 info->pages = LTC3880_NUM_PAGES;
 702                 info->func[0] = PMBUS_HAVE_VIN
 703                   | PMBUS_HAVE_STATUS_INPUT
 704                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 705                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 706                   | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 707                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 708                 info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 709                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 710                   | PMBUS_HAVE_POUT
 711                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 712                 break;
 713         case ltc3883:
 714                 data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
 715                 info->read_word_data = ltc3883_read_word_data;
 716                 info->pages = LTC3883_NUM_PAGES;
 717                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
 718                   | PMBUS_HAVE_STATUS_INPUT
 719                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 720                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 721                   | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 722                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 723                 break;
 724         case ltc3886:
 725                 data->features |= FEAT_CLEAR_PEAKS | FEAT_NEEDS_POLLING;
 726                 info->read_word_data = ltc3883_read_word_data;
 727                 info->pages = LTC3880_NUM_PAGES;
 728                 info->func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN
 729                   | PMBUS_HAVE_STATUS_INPUT
 730                   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 731                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 732                   | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
 733                   | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP;
 734                 info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 735                   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 736                   | PMBUS_HAVE_POUT
 737                   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP;
 738                 break;
 739         default:
 740                 return -ENODEV;
 741         }
 742
 743 #if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
 744         info->num_regulators = info->pages;
 745         info->reg_desc = ltc2978_reg_desc;
 746         if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
 747                 dev_err(&client->dev, "num_regulators too large!");
 748                 info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
 749         }
 750 #endif
 751
 752         return pmbus_do_probe(client, id, info);
 753 }
 754
 755 #ifdef CONFIG_OF
 756 static const struct of_device_id ltc2978_of_match[] = {
 757         { .compatible = "lltc,ltc2974" },
 758         { .compatible = "lltc,ltc2975" },
 759         { .compatible = "lltc,ltc2977" },
 760         { .compatible = "lltc,ltc2978" },
 761         { .compatible = "lltc,ltc2980" },
 762         { .compatible = "lltc,ltc3880" },
 763         { .compatible = "lltc,ltc3882" },
 764         { .compatible = "lltc,ltc3883" },
 765         { .compatible = "lltc,ltc3886" },
 766         { .compatible = "lltc,ltc3887" },
 767         { .compatible = "lltc,ltm2987" },
 768         { .compatible = "lltc,ltm4675" },
 769         { .compatible = "lltc,ltm4676" },
 770         { .compatible = "lltc,ltm4686" },
 771         { }
 772 };
 773 MODULE_DEVICE_TABLE(of, ltc2978_of_match);
 774 #endif
 775
 776 static struct i2c_driver ltc2978_driver = {
 777         .driver = {
 778                    .name = "ltc2978",
 779                    .of_match_table = of_match_ptr(ltc2978_of_match),
 780                    },
 781         .probe = ltc2978_probe,
 782         .remove = pmbus_do_remove,
 783         .id_table = ltc2978_id,
 784 };
 785
 786 module_i2c_driver(ltc2978_driver);
 787
 788 MODULE_AUTHOR("Guenter Roeck");
 789 MODULE_DESCRIPTION("PMBus driver for LTC2978 and compatible chips");
 790 MODULE_LICENSE("GPL");